A pulsating flow in a pipe and the visualized flow pattern of the jet from the pipe

The high-speed pulsating flow is found in the exhaust system of the reciprocating internal combustion engine, the piping system connected to reciprocating compressor etc., and has various features which never exist in the steady flow. This work is concerned with an experimental study of the high-speed pulsating flow in a straight pipe and the jet discharged by the pipe. In order to express quantitatively the intensity of compression wave in the pipe, the "intensity of compression wave" is defined and discussed. The shock formed in vortex ring in the issuing jet from the pipe is found to be due to Laval nozzle effect. The schlieren pictures taken with optical path inclined to the jet axis shows that the decay of vortex ring depends on the speed of the rotary valve.